The present invention pertains generally to the field of coaster brake hubs and, in particular, to coaster brake hubs for wheelchairs.
Coaster brake hubs have, for decades, been used on bicycles. On bicycles, the rear wheel typically includes the coaster brake hub. The typical bicycle coaster brake hub includes a drive shaft connected to the bicycle pedals by way of a chain. When the bicycle is peddled forward, the drive shaft will rotate the hub and rear wheel forward, whereas pedalling the bike in the opposite direction will engage the brake. Generally, the rear wheel will be free to rotate (coast) in a forward direction if the peddles are neither rotated in a forward direction or in the opposite direction. Coaster brake hubs have also been suggested for use on vehicles other than bicycles.
A typical coaster brake hub is disclosed by Agrillo for use with a wheelchair in U.S. Pat. No. 4,758,013. The coaster brake hub disclosed by Argillo has a first mode of operation in which rotation of the drive shaft in a first direction rotates the hub in a first direction and rotation of the drive in the opposite direction brakes the rotation of the hub. This mode of operation is substantially similar to the mode of operation discussed above with regard to typical bicycle coaster brake hubs. Agrillo further discloses, however, a reverse enable lever which can be moved from a configuration in which the hub operates in the first mode to a configuration in which the hub is placed in a second mode of operation. In the second mode of operation, rotation of the drive shaft in the first direction results in rotation of the hub in the first direction and rotation of the drive shaft in the opposite direction results in rotation of the hub in the opposite direction. In the second mode of operation, the hub may be rotated in a first direction and a second direction, however, braking in the second mode is not provided for.